Tool holder



Nav. 8, 1927.

v G. w. navi-:R 1,648,380

TooL mammal Filed Sept, 10. 1924 Patented Nov. 8, i927.'

GEORGE w. DOVER, or LONGMEADOW, nnoDn` IsLAND,

Y I AssIeNon, BY DIRECT AND MnsNE ASSIGNMENTS, To THE Monreoiann `TOOL AND ivInorriNnnY COMPANY, A CORPORATION or nnonn ISLAND.

TOOL HOLDER.

Application filed September 10,1924. Serial No: 7737,015.

' This invention relates to a tool holder such as lis particularly adapted Jriorl holding a p iltal cutting tool in lathes, shapersfand the 1 e. The principal object ot the present invention to provide a tool holder of simple construction, the part-s Ot" which can be readily and easily made, and which is adapted to firmly clamp the cutting tool -in such a manneras to securely hold the same against angular movement while the tool engages the work.

Another vobject oi the invention is lto provide a construction in which a tool Arectangular on three sides and having its? remaining side inclined may be forced in a slightly ,angular direction into a rectangular groove whereby angular movement or chattering `of the cutting tool is prevented.

Another object Ot the invention is the provision of a structure wherein'the cutting tool is automatically and positively located in the proper cutting position when inserted in the holder' and firmly held against movement from thatposition.

Other objects and advantages of the invention relate to certain l improved details Yof construction and methods ot operation as will beV more fully set forth in the detailed description to follow.

Referring to the accompanying drawings forming a partot this application Fig. 1 is a vertical longitudinal sectional View through the tool holder showing the position O the cutting ytool therein.

Fig. 2 is an end elevational View of the tool holder, and, y

Fig. 3 is a vertical transverse sectional view taken along the line 3-3 of Fig. 1.

In the'manufactureot tool holders ot the character described, various eXpedients nave been adopted for' the purpose of permittingA adjustment of the cutting tool and forming the holder in 4such a Vmanner as to take a rectangular cutting tool without breaching an .opening for the same, but so far as I am aware all 'such holders are objectionable'in that they fail to hold the cutting tool firmly against 4movement when in operation an the cutting tool is also liable to rotater slightly whereby the cutting edge is turned'somewhat out of its proper position and the cortesi' @Patat-1.91.1 tef the Sani@ prevented# V- In the structure shown herewith 1 designates the tool holder generally which is provided with a shank'portio'n 2 and a head portion 3. AV passage l extends in an yangu-v lar direction through the holder, the forward portion of which passage is enlarged as indicated at 5 t'or' the reception of a bearf ing block .6 which is substantially semi-cin cular in cross sectional outline and which is provided with a rectangular groove" 7 normed upon theiat -face 8 thereof, the rectangular groove 7 being so formed in the bearing block that it is tilted or inclined somewhat relative to the vflat ytace 8 of the bearing block as shown` in Figs. 2 and 3 ot the drawings; i A pin 9 isv inserted in suitable registering openings 10 and 1l formed in the base of the holder and the bearing block respectively for irmly holding the bearing block against ro-v tation. The openings 10 and 11 are properly formed to locate the bearing block in proper vangular position to so positionthe cutting tool as to maintain ythe cutting edge at the` correct angle for the desired'purpose.

lThe head portion at a `slight angle to the vertical plane ofthe shank 2 asshown in Fig. 2 of the drawings, in the structure shownthe head portion being tilted to the left of the plane ot the shank vfor a right-handed rcutting tool holder, although it isto head portionrwould be tilted in the opposite direction relative to the vertical plane of the shank to provide a left handed cutting tool holder. l 'K A screw 12 is threaded in the head portion 3 ot the holder, the screw being tilted or inclined relative to the vertical plane of the shank portion in order that it may bear squarely upon the upper tacell of the cutting tool 15. Theline A--B indicates the vertical plane of the shank and C-D designates the axis ,of the screwl2 on Fig. 2 of Vthe drawings. Y The bearing Vblock 6 vmay kextend into the enlarged portion 5' of .the passage 4: a suflicient distance to bear against the shoulder 16.

The cutting tool l5 is substantiallyfrectangular in cross-section upon three sides, the upper tace l-lbeingl-properly inclined to give the correct cutting angle. It will 3 of the holder is formed be understood that ,they

vertical plane ofthe shank 2 to the same Yzo degree that the upper face 14: ot the cutting tool is inclined to one Vside thereof thus4 resulting in the screw l2 bearing upon the cutting toolv at right angles to the upper surlace la thereof. y

In the use of the ordinary rectangular cutting tool it is necessary to lgrindL oii'an angular' portion trom oneV side oi thc .cutting tool to'torm a' proper clearance angle and to grind oti'asimilar angular Vportion from the upper tace-ot the cutting tool to forma secondy clearance angle. Y 1 y The grinding'ot these clearance angles throughout the entire effective length ofthe tool involves considerable time and expense which is entirely overcome by the production Vot a cutting tool of the form illustrated herein'where the cross-section ott-he cutting' tool vis in the form ot' a trapezoid having two of its adjacentangles right angles, or in other words the cutting tool is rectangular on three sides with its fourth or top side inclined relative to the base. yThe angle of inclination of the top face ot the tool relative to the base is substantially equal to the sum of the'two clearance angles ahove described.v In this way hy tilting the cutting tool tothe necessary degreeto give proper side clearance the top oit the .cutting tool 'will he so positionedfas to give a proper clearance for turningthe metal removed.

kIt will he seen, therefore, that my' improved tool holder provides a structure wherein a hearing may be provided for a rectangular cutting tool without the trouble and expense'of hroaching an opening for the reception of the same. rlhe hearing block 6 being pinned to the holder is positively prevented from rotation thus insuring proper positioning of the Vcutting edge at all times and ohviating the necessity of the operator adjusting the cutting tool before each opera tion..

The rectangular groovef in the hea-ring block being tilted or inclined relative to the vertical plane of the shank, and the screw- 12 being also V4inclined to thesame'v degree relative to the vertical plane ot 4the shank causes they screw l2 'to hear squarely upon .the lupper surface of the cutting tool and forces the cutting tool downward into the lower edge of the groove thus lirmlyholding the cutting tool in position so that the strain of cutting will not move or rotate the cutter 1n the slightest,degree'and insure that the cutting edge 01 the tool will always loe in the proper angular position'tor operation.

said holder being lrespect tothe intermediate of said three longitudinal faces. The end 13 of the cutting tool is ground atan inclination to form a cutting edge along the line it maires with the inclined longitudinal tace lect thefcutting tool. In the use ot tools of this charac-` ter it has been necessary heretofore for' the workman to grind three clearance angles;

namely at the top, side and front end ofthe cutting tool.v 'By forming the cutting tool with an inclined longitudinal tace la and properly positioning the same in the tool holder the necessity or'grinding the top clearance and side clearance angles is 0hviated, and a tool is provided which is capable of being used without grinding e2;- cept for the grinding ofthe front clearance angle at the end oi' the cutting tool. Inpositioning the cutting tool in the holder' it will be'seen that rthe saine is tilted or inclined somewhat from the vertical, whereby] the cutting tool is so positioned that `upon tightening the rscrew l2 two of rthe rectangular longitudinal sides of the cutting tool are forced into intimate contact with-the hase and one side tace ot the groove 7- to. hold theV tool firmly againstmovement, and at the same time so incline the tool as to. pro vvide a side clearanceangle as well as'atop .clearance angle.

ylVhat I claimis:- y

l. A tool holder provided with a Vshank portion and a head portion inclined relative to the vertical plane of the *shank portion, provided with a circular tool receiving passage, a segmental bearing lolocl locatedlin said passage and provided with a rectangular groove tilted with respect to the upper face of said block, means for retaining said hearing block in a predetermined position within said passage, a cutting tool fitting in said rectangular groove, and

a clamping screw threaded in the head portion of said holder and bearing ldirectly upon the upper face of said cntting'tool to lirmly secure the same against 'rotative movement.

2. A tool holderrincluding a shank portion and ahead portion and provided with an opening of circular cross-section,a hearing block of segmental cross-sectionixedly l secured within said opening andfprovided upon its Vplane face with a rectangular groove inclined relative to the plane of the block, a cutting' tool positioned in Said groove, and a screw threadedinjsaid'head portion land inclined relative to the vertical plane of said shank portion 'and bearing upon the upper face of .Said tQOl. tQ QITGG two sides of said tool firmly into Contact WithV two sides of said groove andrhold the tool trmly in cutting position.

i3. A tool holder comprising a shank portion and a head portion and provided with a circular opening, a segmental bearing block positioned in said opening and held against rotative movement therein, said bearing block being provided with a rectangular groove and so positioned in said opening that the rectangular groove is inclined With respect to the horizontal, a cutting tool provided With three longitudinal rectangular faces,

the lfourth longitudinal face of said cutting tool heing inclined relative to-the plane of the intermediate rectangular face, said cutting tool loeingy positioned in said groove with its inclined face located adjacent to the open side of said groove, and a screw threaded in said head portion and bearing against the inclined face of said Cutting tool to hold the same firmly in cutting position'.

Inv testimony whereof I have aliixed my signature.

GEORGE DOVER. 

